JP5511360B2 - Image display device - Google Patents

Description

  The present invention relates to an image display device, and more particularly to an image display device using a reflective image display element.

  An image display apparatus using a conventional reflective liquid crystal panel (image display element) needs to have different optical paths for incident light and reflected light with respect to the liquid crystal panel. Therefore, a polarizing beam splitter that transmits P-polarized light and reflects S-polarized light is disposed on the incident / exit surface side of the reflective liquid crystal panel. The characteristics of the polarization separation film of the polarization beam splitter depend on the incident angle of incident light. As the incident angle of the light incident on the polarization separation film is further away from 45 °, the amount of leaked light in the polarization separation film increases and the contrast of the projected image decreases. Leakage light is light that enters the projection lens when the liquid crystal panel is driven so that all pixels display black.

  Patent Document 1 discloses a technique in which an analyzer that blocks leakage light is disposed on the exit surface side of a polarization beam splitter in order to improve the contrast of a projected image. More specifically, the light emitted from the light source passes through the polarization separation film of the polarization beam splitter and is guided to the reflective liquid crystal panel. When performing white display, the P-polarized light is modulated into S-polarized light by the liquid crystal panel, and is again detected by the polarizing beam splitter and reflected to the projection lens side. On the other hand, when performing black display, the P-polarized light is reflected without being modulated, passes through the polarization separation film, and is returned to the light source side. When this black display is performed, leakage light that enters the projection lens is generated despite the P-polarized light. In Patent Document 1, a polarizing plate is disposed on the exit surface side of the polarizing beam splitter, thereby blocking leakage light and improving contrast.

Japanese Patent Publication No. 3-175437

However, since the polarizing plate has low transmittance, there is a problem that the brightness of the projected image is lowered.
Therefore, an object of the present invention is to suppress a decrease in brightness and improve contrast.

  In order to solve the above problems, the present invention provides an image display element that displays an image by controlling a polarization state of a polarized light beam, an illumination optical system that guides the polarized light beam to the image display element, and the illumination optical system. A polarizing beam splitter having a polarization separation film for detecting incident light by reflecting S-polarized light and transmitting P-polarized light between the image display element and an image displayed on the projection surface by the image display element A projection optical system that attaches the projection optical system, and emits from the center of the image display element in a cross section parallel to the normal line of the polarization separation film and the normal line of the image display element. The angle formed between the optical path of the light ray incident on the intersection of the optical surface closest to the image display element and the optical axis of the projection optical system and the polarization separation film is less than 45 °.

  The effect of the present invention is that a high-contrast image display apparatus can be provided.

The figure which shows 1st Embodiment of the image display apparatus of this invention. Enlarged view around the polarizing beam splitter and image display device The figure which shows the relationship between the incident angle of light with respect to the polarization separation film and the characteristics of the polarization separation film Explanatory drawing of leaking light from polarizing beam splitter Schematic diagram of the angular distribution of leakage light of the polarization separation film in the first embodiment Schematic diagram of the amount of light that the projection lens can capture and its angular distribution Sectional drawing of 2nd Embodiment of the image display apparatus of this invention. Schematic diagram of angular distribution of leakage light of polarization separation film in the second embodiment The figure which shows 3rd Embodiment of the image display apparatus of this invention.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

(Embodiment 1)
FIG. 1 shows a configuration diagram of a first embodiment of an image display apparatus. In the figure, 1 is a light source, and 2 is a reflector that reflects light from the light source 1 in a predetermined direction. In the present embodiment, a parabolic reflector is used. 3a is a first fly-eye lens in which rectangular lenses similar in shape to the panel are arranged in a matrix, and 3b is a second fly-eye lens having lenses corresponding to the individual lenses of the first fly-eye lens 3a. 4 is a polarization conversion element that aligns non-polarized light from the light source with linearly polarized light, 5a and 5b are condenser lenses, and 6 is a reflecting mirror. 7 is a polarization beam splitter, 8 is a polarization separation film of the polarization beam splitter 7, 9 is a reflective liquid crystal panel (image display element) that displays an image by controlling the polarization state of incident light, and 10 is a projection lens (projection). An optical system) 11 is a screen (projection surface). The projection lens is attached to an attachment port (attachment portion) in the image display apparatus main body. A line segment L is an optical path of a light beam that is emitted from the center of the image display element and reaches the point where the optical axis of the projection lens 10 and the optical surface closest to the illumination optical system in the projection lens (projection optical system) intersect. The projection lens is arranged so that the angle formed by the optical path L and the polarization separation film 8 of the polarization beam splitter 7 is less than 45 °. The most optical element in the illumination optical system in the projection optical system is, for example, the lens closest to the liquid crystal panel of the projection lens. The refractive index n of the polarizing beam splitter 7 is larger than 1.6, and the refractive index n of the polarizing beam splitter of this embodiment is 1.8. The point at which the optical axis of the projection lens 10 exits from the center of the image display element and the optical surface closest to the illumination optical system in the projection lens intersects is the surface vertex of the optical surface closest to the reduction side in the projection lens. . Further, the incident angle of the light emitted perpendicularly to the liquid crystal panel from the center of the liquid crystal panel with respect to the polarization separation film is 45 °. 1 represents the optical axis of the condenser lens 5a or the optical axis of the projection lens. A one-dot chain line from the reflection mirror 6 to the liquid crystal panel 9 is a normal line of the liquid crystal panel and represents a line passing through the approximate center of the polarization separation film 8.

  The light emitted from the light source 1 is reflected by the reflector 2 to become substantially parallel light, is incident on the first fly-eye lens 3a, and is separated into a plurality of light beams by individual lenses forming the first fly-eye lens. Is done. The plurality of divided light beams pass through the second fly-eye lens 3 b and enter the polarization conversion element 4. The polarization conversion element 4 has a structure in which a plurality of small polarization beam splitters (small polarization beam splitters) each having a polarization separation film are arranged, and every other half-wave plate is disposed on the exit surface of the polarization beam splitter. Non-polarized light incident on the polarization conversion element 4 is aligned with P-polarized light (polarized light beam) and emitted. If it is desired to align with S-polarized light, a half-wave plate may be arranged on the exit side of P-polarized light to align with S-polarized light. In that case, the position of the liquid crystal panel 9 is arranged on the side where the incident light of the polarization beam splitter 7 is reflected. Here, the P-polarized light and the S-polarized light are defined not for the small polarization beam splitter of the polarization conversion element 4 but for the polarization separation film 8 of the polarization beam splitter 7 adjacent to the liquid crystal panel (image display element) 9. The light aligned with the P-polarized light by the polarization conversion element 4 is guided to the reflection mirror 6 while being converged by the condenser lenses 5a and 5b. The light source 1 to the condenser lenses 5a and 5b serve as an illumination optical system, and this illumination optical system is Koehler illumination that uniformly illuminates the liquid crystal panel.

  The convergent light emitted from the condenser lenses 5 a and 5 b is reflected by the reflecting mirror 6 and enters the polarizing beam splitter 7. The P-polarized light passes through the polarization separation film 8 of the polarization beam splitter 7 and illuminates the liquid crystal panel 9. Incident light is modulated by the liquid crystal panel 9, reflected by the polarization beam splitter, and projected onto the screen 11 by the projection lens 10. The Z axis in the figure is an axis parallel to the optical axis of the projection lens, and the direction toward the screen is the + Z direction. The X axis is an axis perpendicular to the plane including the Z axis and the normal line of the polarization separation film 8, and the direction from the back to the front of the paper is the + X direction. The Y axis is an axis perpendicular to the X axis and the Z axis, and the direction from the bottom to the top of the paper is defined as the + Y direction.

  FIG. 2 shows an enlarged view around the polarizing beam splitter 7 and the liquid crystal panel 9 of FIG. The angle θ formed by the optical path L (solid line in FIG. 2) and the polarization separation film 8 is less than 45 °. A broken arrow is a light beam for black display. The P-polarized light reflected by the reflection mirror passes through the polarization separation film 8 and enters the liquid crystal panel 9. The incident P-polarized light is reflected in the P-polarized state without being changed in the polarization direction when black display is performed, passes through the polarization separation film 8 again, and returns to the light source side. Most of the light is returned to the light source side, but due to the characteristics of the polarization separation film, there is light that is reflected by the polarization separation film and incident on the projection lens side regardless of the P-polarized light.

  FIG. 3A is a graph showing changes in the polarization separation film characteristics with respect to changes in the incident angle of the incident light on the polarization separation film 8 in the XY cross section (X direction). FIG. 3B is a graph showing changes in the polarization separation film characteristics with respect to changes in the incident angle of the incident light on the polarization separation film 8 in the YZ cross section (Y direction). The horizontal axis represents wavelength (nm), and the vertical axis Rp represents the reflectance (%) of P-polarized light. Here, the smaller the Rp, the higher the extinction ratio and the better the characteristics of the polarization separation film. The solid line in the graph represents the characteristics of the polarization separation film with respect to light rays incident on the polarization separation film at 45 °. The broken line in the graph represents the characteristics of the polarization separation film with respect to light rays incident at an angle of about 5 ° smaller than 45 °. The alternate long and short dash line represents the property of the polarization splitting film with respect to a light ray incident at an angle approximately 5 ° larger than 45 °. Also, the polarization separation film having the characteristics shown in FIGS. 3A and 3B satisfies the performance in the green wavelength range 500 to 580 (nm), which has the highest relative visibility in the spectrum of the light source used in the image display device. It is designed as follows.

  3A and 3B, when the incident angle of the light beam is changed by the same angle with respect to the light beam incident at 45 ° with respect to the normal line of the polarization separation film 8, the incident angle is changed in the YZ section. It can be seen that the variation in the characteristics of the polarization splitting film is larger when it is used. That is, it can be seen that the polarization separation film has better characteristics with respect to changes in the incident angle in the XY section (X direction) than characteristics with respect to changes in the incident angle in the YZ section (Y direction).

  Further, attention is paid to the change in the angle of the YZ section in FIG. In the YZ cross section, when the incident angle is changed between + 5 ° and −5 °, it can be seen that the change in characteristics is different from that in FIG. This is based on the film thickness through which the incident light beam passes at 45 ° with respect to the normal line of the polarization splitting film. When the incident angle of the light beam changes by + 5 ° in the Y direction, the film thickness through which the incident light beam passes increases (longer). This is because when it changes by −5 °, it becomes thinner (shorter). Further, it can be seen that the peak position of the graph (arrow in FIG. 3B) is shifted to the short wavelength side when the incident angle is 45 + 5 °, and to the long wavelength side when 45-5 °. In general, it is known that the characteristics of an optical film shift to the long wavelength side when the thickness of the film through which the light passes decreases and to the short wavelength side when it increases. For this reason, when light in the green wavelength region (500 to 580 nm) is incident, the amount of leakage light is smaller when the incident angle is 45 + α ° than when 45-α °. FIG. 4 is a diagram for making it easy to understand whether there is much or little leakage light in the cross section of FIG. As shown in FIG. 4, the amount of leakage light of light (P-polarized light) reflected from a certain point of the liquid crystal panel 9 is small in the + Y direction and large in the −Y direction on the exit surface of the polarization beam splitter 7. Become.

  FIG. 5 is a schematic diagram showing the incident angle of light rays incident on the polarization separation film and the distribution of leakage light in the XY section when the liquid crystal panel 9 is driven so that the projected image is displayed in all black. The coordinate axis represents the incident angle with respect to the polarization separating film 8, and the center represents that the angle deviation from 45 ° is 0 °. The lighter the part, the less light leaks, and the darker the part, the more light leaks. The coordinate axes in the figure correspond to the coordinate axes in FIGS. As described with reference to FIG. 3, as shown in FIG. 5, the leakage light that causes a decrease in contrast is symmetric in the X direction but asymmetric in the Y direction, and particularly leaks in the −Y direction. More light. The angle distribution of leakage light as shown in FIG. 5 is confirmed by displaying an all-black image on an actual image display device and directly observing light rays from the image display element on the screen except for the projection lens. be able to.

  Next, the angular distribution of light rays that can be captured by the projection lens 10 will be described. Attention is paid to the path from the light that diverges from the liquid crystal panel 9 to the projection lens reaches the screen via the projection lens. The point corresponding to the center of the optical axis of the projection lens, that is, the light beam diverging from the center of the liquid crystal panel in FIG. 1, takes in all the angle components defined by the F number of the projection lens. However, a part of the angle component of the light beam diverging from a point away from the point corresponding to the optical axis center of the projection lens is blocked by the vignetting of the projection lens. Vignetting means that the more the angle of the incident light beam is oblique to the optical axis of the projection lens, the less the incident light beam passes through the entire stop due to the size and thickness of the lens. Generally, the projection lens of an image display device (projector) is generally used with its projection direction inclined. The configuration shown in FIG. 1 also projects an image obliquely upward. When an image is projected in an oblique direction, the angular distribution of rays that can be captured by the projection lens by vignetting also becomes asymmetric in the Y direction. For reference, FIG. 6 shows a schematic diagram of the amount of light that can be taken in by the projection lens and the angular distribution when the light beam having a substantially uniform light amount distribution is incident on the projection lens. It can be seen that there is little loss of the amount of light that can be taken in in the + Y direction with little influence of vignetting. Conversely, the amount of light that can be captured in the −Y direction is small due to the effect of vignetting.

  In the present invention, the projection lens is arranged with respect to the image display element in view of the angular distribution of leaked light due to the characteristics of the polarization separation film shown in FIG. That is, let L be the optical path of a light beam that is emitted from the liquid crystal panel and reaches the point where the optical axis of the projection lens and the optical surface closest to the illumination optical system in the projection lens intersect. The projection lens is arranged so that the angle formed by the optical path L and the polarization separation film 8 of the polarization beam splitter 7 is less than 45 °. In other words, the optical axis of the projection lens or the axis passing through the center of the projection lens attachment port (attachment part) is a line that forms 45 ° with respect to the polarization separation film and is parallel to the optical axis of the projection lens. And a projection lens arranged between the illumination optical system and the optical axis of the illumination optical system. In other words, the optical axis of the projection lens is arranged so as to be 45 ° with respect to the polarization separation film and not coincide with the line parallel to the optical axis of the illumination optical system.

  In the present invention, since the optical axis of the projection lens (projection lens mounting port) is shifted to the side with less leakage light, the leakage light generated in the polarization separation film is utilized by the effect of vignetting inside the projection lens. It can be effectively blocked. Thereby, the leakage light contained in a projection image is reduced and the contrast of a projection image improves.

(Embodiment 2)
FIGS. 7A and 7B are views showing a second embodiment of the image display device of the present invention. The difference from the first embodiment is that the illumination optical system has a function of compressing the light beam in the first cross section (XZ cross section) and the second cross section (YZ cross section) that include the optical axis of the illumination optical system and are orthogonal to each other. It is a point. FIG. 7A is a diagram of the image display device according to the second embodiment as viewed from the XZ cross section, and FIG. 7B is a diagram of the image display device according to the second embodiment as viewed from the YZ cross section.

  7A and 7B, 1 is a light source, 2 is a reflector that reflects light from the light source 1 in a predetermined direction, and 12 is a convex lens (positive lens). Reference numeral 13 denotes a concave cylindrical lens (a lens having negative refractive power in the X direction and no refractive power in the Y direction), and reference numeral 14 is a concave cylindrical lens (having no refractive power in the X direction and negative refractive power in the Y direction). Lens). In other words, 13 is a first negative cylindrical lens, and 14 is a second negative cylindrical lens. 3a is a first fly-eye lens in which rectangular lenses similar in shape to the panel are arranged in a matrix, and 3b is a second fly-eye lens having lenses corresponding to the individual lenses in 3a. Reference numeral 4 denotes a polarization conversion element having a role of aligning non-polarized light from the light source with linearly polarized light. 5a and 5b are condenser lenses, 6 is a reflection mirror, 7 is a polarization beam splitter, 8 is a polarization separation film, 9 is a reflective liquid crystal panel (image display element), 10 is a projection lens, and 11 is a projection screen (screen). is there. The condenser lenses 5a and 5b may be a single convex lens. In this embodiment, a high-pressure mercury lamp is used as the light source, and a parabolic mirror is used as the reflector. As in the first embodiment, the image display apparatus main body has an attachment port for attaching the projection lens, and the projection lens is attached to the attachment port.

  The light emitted from the light source 1 is collected by the reflector 2 and enters the convex lens 12. The light is converged by the convex lens 12 and is incident on the concave cylindrical lens 13. In the cross section of FIG. 6A, the light is emitted as substantially parallel light in the X direction by the convex lens 12 and the concave cylindrical lens 13 (negative cylindrical lens). The light rays incident on the first fly-eye lens 3a are separated into a plurality of light beams by the individual lenses forming the first fly-eye lens. The light that has passed through the first fly-eye lens 3a is emitted as substantially parallel light by the convex lens 12 and the concave cylindrical lens 14 positioned in front of the second fly-eye lens 3b in the cross section of FIG. 7B. The light beams compressed in the XZ cross section and the YZ cross section pass through the second fly-eye lens 3 b and enter the polarization conversion element 4. The light aligned with the P-polarized light by the polarization conversion element 4 is converged by the condenser lenses 5 a and 5 b, reflected by the reflection mirror 6, and incident on the polarization beam splitter 7. The light incident on the polarization beam splitter 7 passes through the polarization separation film 8 and illuminates the liquid crystal panel 9. When performing white display, the liquid crystal panel 9 modulates P-polarized light into S-polarized light. The light modulated by the liquid crystal panel 9 is reflected by the polarization separation film 8 of the polarization beam splitter and projected onto the screen 11 by the projection lens 10. When black display is performed, the liquid crystal panel 9 reflects the polarization direction of the P-polarized light without converting it. The light reflected by the liquid crystal panel 9 passes through the polarization separation film 8 and is returned to the light source side. The illumination optical system according to the second embodiment also performs Koehler illumination by arranging the light source and the second fly-eye lens at a conjugate position, and arranging the first fly-eye lens and the liquid crystal panel at a conjugate position.

  Also in the present embodiment, according to a change in the angle at which the light beam reflected from the liquid crystal panel enters the polarization separation film of the polarization beam splitter, the polarization separation characteristic varies, and leakage light that lowers the contrast is generated. FIG. 8 shows a schematic diagram of the angular distribution of leakage light in the polarization separation film when the light beam is modulated into a polarization state corresponding to the all black image in the liquid crystal panel. The coordinate axis represents the incident angle with respect to the polarization separating film 8, and the center represents that the angle deviation from 45 ° is 0 °. The lighter the part, the less light leaks, and the darker the part, the more light leaks. The coordinate axes in the figure correspond to the coordinate axes in FIG. In this embodiment, the light beam is compressed independently in the X direction and the Y direction, and the compression rate of the light beam in the Y direction is higher than that in the first embodiment.

  Similarly to the first embodiment, the light path of the light beam that is emitted from the center of the liquid crystal panel and reaches the point where the optical axis of the projection lens 10 and the optical surface closest to the illumination optical system in the projection lens intersect is L. The angle e formed between the optical path L and the film boundary line of the polarization separation film on the YZ plane is set to be less than 45 °. Therefore, leakage light in the −Y direction can be effectively blocked by the influence of vignetting inside the projection lens. Therefore, the contrast can be improved without inserting a polarizing plate or the like for cutting the leaked light.

  As another effect of the present invention, by changing the compressibility in the X direction and the Y direction and compressing more strongly in the Y direction, the incident angle to the polarization separation film is widened in the Y direction where the fluctuation of the characteristics of the polarization separation film is large. Can be made smaller. As a result, the amount of leakage light is reduced as compared with the case where the light beams in the X and Y directions are compressed by the same amount. In this specification, compression is to make the width of the light beam after exiting a substantially afocal optical system smaller than the width of the light beam before incidence, and the compression rate is that rate.

(Embodiment 3)
FIG. 9 is a diagram showing a third embodiment of the image display apparatus of the present invention. Only parts different from FIG. 1 will be described. The polarization conversion element 4 aligns the polarization direction of the incident light with P-polarized light. Reference numeral 15 denotes a dichroic mirror (color separation element), and reference numeral 16 denotes a wavelength selective phase plate, which is an element that acts only on light in the red wavelength band and rotates its polarization direction by 90 °. 19 is a reflective liquid crystal panel for red (first image display element), 20 is a reflective liquid crystal panel for green (second image display element), and 21 is a reflective liquid crystal panel for blue (third image). Display element). Reference numeral 22 denotes a synthesis prism (synthesis element) that reflects light in the green wavelength band and transmits light in the red and blue wavelength bands. 9 represents the optical axis of the condenser lens 5a or the optical axis of the projection lens.

  The light beam emitted from the condenser lens 5 b enters the dichroic mirror 15. Of the incident light, the dichroic mirror 15 transmits only light in the green wavelength band (first color light), and reflects light in the blue band and red band (second and third color lights). The light in the green band is analyzed by the polarization beam splitter 17 (first polarization beam splitter), and illuminates the liquid crystal panel 20 for green. The light converted to S-polarized light by the green liquid crystal panel 20 reflects the polarization beam splitter 17, reflects the combining prism 22, and is projected onto the projection surface by the projection lens. The light whose polarization direction has not been converted by the liquid crystal panel 9 passes through the polarization beam splitter 17 again and is returned to the projection lens side.

  The light in the red band and blue band reflected by the dichroic mirror 15 passes through the wavelength selective phase plate 16. The wavelength-selective phase plate 16 acts only on the red band light and rotates its polarization direction by 90 ° to make S-polarized light. The red band light converted into the S-polarized light is reflected by the polarization separation film of the polarization beam splitter 18 (second polarization beam splitter) and enters the liquid crystal panel 19 for red. The red band light converted into the P-polarized light by the liquid crystal panel 19 is transmitted through the polarization beam splitter 18 and the combining prism 22 and then projected onto the projection surface by the projection lens 10. S-polarized light in the red band that has not been converted by the liquid crystal panel 19 is reflected by the polarization separation film of the polarization beam splitter 18 and returned to the light source side.

  The blue band light reflected by the dichroic mirror 15 passes through the wavelength selective phase plate 16, passes through the polarization beam splitter 18, and enters the blue liquid crystal panel 21. After being incident on the blue liquid crystal panel, the light converted from P-polarized light to S-polarized light is reflected by the polarization beam splitter 18, passes through the combining prism 22, and is projected onto the projection surface by the projection lens. The P-polarized light that has not been converted by the liquid crystal panel 21 passes through the polarization beam splitter 18 and is returned to the light source side.

  Similar to the description in the first embodiment, the light beam reflected from the liquid crystal panel 20 changes in the polarization separation characteristic according to the change in the angle at which the light beam is incident on the polarization separation film of the polarization beam splitter 17, and leakage light that reduces the contrast is generated. To do.

  Here, when attention is focused on leakage light in the green wavelength region that contributes most to brightness, the extinction ratio of P-polarized light is reduced with respect to an angular change in which the thickness of the polarization separation film through which the light passes is reduced as in the first embodiment. Let L be the optical path of a light beam that exits from the center of the liquid crystal panel 20 and reaches the point where the intersection of the optical surface closest to the illumination optical system and the optical axis of the projection lens 10 intersects. The angle e formed by the optical path L and the film boundary line of the polarization separation film on the YZ step surface is configured to be less than 45 °. Therefore, leakage light in the −Y direction can be effectively blocked by the influence of vignetting inside the projection lens. As described above, leakage light can be suppressed without disposing a polarizing plate having low transmittance on the exit side of the polarizing beam splitter, so that it is possible to improve contrast while suppressing a decrease in brightness of the projected image.

  As another effect, the image projection apparatus can be downsized in the direction in which the projection lens can be shifted (XY direction in FIG. 9). This is because the optical axis of the projection lens is arranged inside the housing.

  As mentioned above, although preferable embodiment of this invention was described, this invention is not limited to these embodiment, A various deformation | transformation and change are possible within the range of the summary. For example, the light source may be a laser light source that emits linearly polarized light. Further, the characteristics of the dichroic mirror 15 and the characteristics of the combining prism may be changed to transmit red band light and transmit blue band light and green band light. Further, the present invention can also be applied to an image display device in which three polarization beam splitters are arranged in each of three color liquid crystal panels using a cross dichroic prism.

DESCRIPTION OF SYMBOLS 1 Light source 3a 1st lens array 3b 2nd lens array 4 Polarization conversion element 5a, 5b Condenser lens 6 Reflection mirror 7 Polarization beam splitter 8 Polarization separation film 9 Reflection type liquid crystal display element 10 Projection lens 11 Screen

Claims (16)

An image display element that displays an image by controlling the polarization state of the polarized light beam;
An illumination optical system for guiding the polarized light beam to the image display element;
A polarization beam splitter having a polarization separation film that detects incident light by reflecting S-polarized light and transmitting P-polarized light between the illumination optical system and the image display element;
And a mounting portion for mounting a projection optical system for projecting an image displayed by the previous SL image display device on the projection surface,
An optical surface that exits from the center of the image display element and is closest to the image display element in the projection optical system and the projection in a cross section parallel to the normal line of the polarization separation film and the normal line of the image display element An image display device, wherein an angle formed between an optical path of a light beam incident on an intersection with an optical axis of an optical system and the polarization separation film is less than 45 °. The image according to claim 1, wherein a line that forms 45 ° with respect to the polarization separation film and is parallel to the optical axis of the illumination optical system does not coincide with the optical axis of the projection optical system. Display device.   3. The image display device according to claim 1, wherein n> 1.6, where n is a refractive index of the polarizing beam splitter. The illumination optical system includes a positive lens, a first negative cylindrical lens, and a second negative cylindrical lens in order from the light source side toward the projection surface.
The positive lens and the first negative cylindrical lens compress a light beam in a first cross section, and the positive lens and the second negative cylindrical lens pass through the optical axis of the illumination optical system and the first cross section. The image according to any one of claims 1 to 3, wherein the light beam is compressed in a second cross section orthogonal to the first cross section, and the compressibility of the light beam is different between the first cross section and the second cross section. Display device. 5. The image display device according to claim 1, wherein the light incident on the image display element is light in a green wavelength band. 6. First, second and third image display elements for displaying an image by controlling the polarization state of the polarized light beam;
An illumination optical system for guiding the polarized light flux to the first, second and third image display elements;
A color separation element that separates light emitted from the illumination optical system into first color light and second and third color light;
A first polarization beam splitter having a polarization separation film for detecting incident light by reflecting S-polarized light and transmitting P-polarized light between the color separation element and the first image display element;
A second polarization beam splitter having a polarization separation film for detecting incident light by reflecting S-polarized light and transmitting P-polarized light between the color separation element and the second and third image display elements;
The first, organic and synthetic elements for combining the light reflected by the second and third image display elements, and a mounting portion for mounting a projection system that projects the light synthesized by the prior Symbol combining element on the projection surface And
An optical surface that exits from the center of the image display element and is closest to the image display element in the projection optical system and the projection in a cross section parallel to the normal line of the polarization separation film and the normal line of the image display element An image display device, wherein an angle formed between an optical path of a light beam incident on an intersection with an optical axis of an optical system and the polarization separation film is less than 45 °. The image display apparatus according to claim 6 , wherein the first color light is light in a green wavelength band. Image projection apparatus according to any one of claims 1 to 7, characterized in that it has a projection optical system to be attached to the attachment portion. An image display element that displays an image by controlling the polarization state of the polarized light beam;
An illumination optical system for guiding the polarized light beam to the image display element;
A polarization beam splitter having a polarization separation film that detects incident light by reflecting S-polarized light and transmitting P-polarized light between the illumination optical system and the image display element;
A projection optical system that projects an image displayed by the image display element onto a projection surface;
An optical surface that exits from the center of the image display element and is closest to the image display element in the projection optical system and the projection in a cross section parallel to the normal line of the polarization separation film and the normal line of the image display element An image display device, wherein the projection optical system is arranged such that an angle formed between an optical path of a light beam incident on an intersection with an optical axis of the optical system and the polarization separation film is less than 45 °. First, second and third image display elements for displaying an image by controlling the polarization state of the polarized light beam;
An illumination optical system for guiding the polarized light flux to the first, second and third image display elements;
A color separation element that separates light emitted from the illumination optical system into first color light and second and third color light;
A first polarization beam splitter having a polarization separation film for detecting incident light by reflecting S-polarized light and transmitting P-polarized light between the color separation element and the first image display element;
A second polarization beam splitter having a polarization separation film for detecting incident light by reflecting S-polarized light and transmitting P-polarized light between the color separation element and the second and third image display elements;
A combining element that combines the light reflected by the first, second, and third image display elements;
A projection optical system that projects light synthesized by the synthesis element onto a projection surface;
An optical surface that exits from the center of the first image display element and is closest to the image display element in the projection optical system in a cross section parallel to the normal line of the polarization separation film and the normal line of the image display element And the projection optical system is arranged such that an angle formed between the optical path of the light beam incident on the intersection of the projection optical system and the optical axis of the projection optical system and the polarization separation film is less than 45 °. apparatus. An image display element that displays an image by controlling the polarization state of the polarized light beam;
An illumination optical system for guiding the polarized light beam to the image display element;
A polarization beam splitter having a polarization separation film that detects incident light by reflecting S-polarized light and transmitting P-polarized light between the illumination optical system and the image display element;
A mounting portion for attaching a projection optical system that projects an image displayed by the image display element onto a projection surface;
An optical surface that exits from the center of the image display element and is closest to the image display element in the projection optical system and the projection in a cross section parallel to the normal line of the polarization separation film and the normal line of the image display element An image display device, wherein the mounting portion is arranged such that an incident angle of a light beam incident on an intersection with an optical axis of an optical system is larger than 45 ° from the polarization separation film. First, second and third image display elements for displaying an image by controlling the polarization state of the polarized light beam;
An illumination optical system for guiding the polarized light flux to the first, second and third image display elements;
A color separation element that separates light emitted from the illumination optical system into first color light and second and third color light;
A first polarization beam splitter having a polarization separation film for detecting incident light by reflecting S-polarized light and transmitting P-polarized light between the color separation element and the first image display element;
A second polarization beam splitter having a polarization separation film for detecting incident light by reflecting S-polarized light and transmitting P-polarized light between the color separation element and the second and third image display elements;
A combining element that combines the light reflected by the first, second, and third image display elements;
A mounting portion for attaching a projection optical system that projects light synthesized by the synthesis element onto a projection surface;
An optical surface that exits from the center of the first image display element and is closest to the image display element in the projection optical system in a cross section parallel to the normal line of the polarization separation film and the normal line of the image display element The image display apparatus is characterized in that the mounting portion is arranged so that an incident angle of light rays incident on an intersection of the projection optical system and the optical axis of the projection optical system is larger than 45 °. An image display element that displays an image by controlling the polarization state of the polarized light beam;
An illumination optical system for guiding the polarized light beam to the image display element;
A polarization beam splitter having a polarization separation film that detects incident light by reflecting S-polarized light and transmitting P-polarized light between the illumination optical system and the image display element;
A projection optical system that projects an image displayed by the image display element onto a projection surface;
An optical surface that exits from the center of the image display element and is closest to the image display element in the projection optical system and the projection in a cross section parallel to the normal line of the polarization separation film and the normal line of the image display element An image display device, wherein the projection optical system is arranged so that an incident angle of a light beam incident on an intersection with an optical axis of the optical system is larger than 45 °. First, second and third image display elements for displaying an image by controlling the polarization state of the polarized light beam;
An illumination optical system for guiding the polarized light flux to the first, second and third image display elements;
A color separation element that separates light emitted from the illumination optical system into first color light and second and third color light;
A first polarization beam splitter having a polarization separation film for detecting incident light by reflecting S-polarized light and transmitting P-polarized light between the color separation element and the first image display element;
A second polarization beam splitter having a polarization separation film for detecting incident light by reflecting S-polarized light and transmitting P-polarized light between the color separation element and the second and third image display elements;
A combining element that combines the light reflected by the first, second, and third image display elements;
A projection optical system that projects light synthesized by the synthesis element onto a projection surface;
An optical surface that exits from the center of the first image display element and is closest to the image display element in the projection optical system in a cross section parallel to the normal line of the polarization separation film and the normal line of the image display element And the projection optical system is arranged so that an exit angle of a light beam incident on an intersection of the projection optical system and the optical axis of the projection optical system is larger than 45 °. . First, second and third image display elements for displaying an image by controlling the polarization state of the polarized light beam;
An illumination optical system for guiding the polarized light flux to the first, second and third image display elements;
A color separation element that separates light emitted from the illumination optical system into first color light and second and third color light;
A first polarizing beam splitter provided between the color separation element and the first image display element, which detects incident light by reflecting S-polarized light and transmitting P-polarized light;
A second polarization beam splitter provided between the color separation element and the second and third image display elements, which detects incident light by reflecting S-polarized light and transmitting P-polarized light;
A combining element that combines the light reflected by the first, second, and third image display elements;
A mounting portion for attaching a projection optical system that projects light synthesized by the synthesis element onto a projection surface;
The color separation element, the first and second polarization beam splitters are arranged such that a plane including the color separation surface of the color separation element and a plane including the polarization separation surfaces of the first and second polarization beam splitters are orthogonal to each other. An image display device arranged,
The first color light is reflected by the combining element to be combined with the second and third color lights,
In the direction in which the first polarizing beam splitter and the combining element are aligned, the optical axis of the projection optical system is more than the light path on the emission side from the combining element of the light beam that has followed the optical path on the optical axis of the illumination optical system. The image display apparatus is characterized in that the mounting opening is arranged so as to be positioned on the first polarizing beam splitter side. First, second and third image display elements for displaying an image by controlling the polarization state of the polarized light beam;
An illumination optical system for guiding the polarized light flux to the first, second and third image display elements;
A color separation element that separates light emitted from the illumination optical system into first color light and second and third color light;
A first polarizing beam splitter provided between the color separation element and the first image display element, which detects incident light by reflecting S-polarized light and transmitting P-polarized light;
A second polarization beam splitter for detecting incident light by reflecting S-polarized light and transmitting P-polarized light between the color separation element and the second and third image display elements;
A combining element that combines the light reflected by the first, second, and third image display elements;
A projection optical system that projects light synthesized by the synthesis element onto a projection surface;
The color separation element, the first and second polarization beam splitters are arranged such that a plane including the color separation surface of the color separation element and a plane including the polarization separation surfaces of the first and second polarization beam splitters are orthogonal to each other. An image display device arranged,
The first color light is reflected by the combining element to be combined with the second and third color lights,
In the direction in which the first polarization beam splitter and the combining element are aligned, the optical axis of the projection optical system is more than the light path on the emission side from the combining element of the light beam that has followed the optical path on the optical axis of the illumination optical system. And the projection optical system is disposed so as to be positioned on the first polarizing beam splitter side.

Images